U.S. patent application number 10/501228 was filed with the patent office on 2005-06-09 for process for producing modified polymer.
Invention is credited to Chino, Keisuke, Kawazura, Tetsuji, Onoi, Hidekazu.
Application Number | 20050124764 10/501228 |
Document ID | / |
Family ID | 32463312 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050124764 |
Kind Code |
A1 |
Onoi, Hidekazu ; et
al. |
June 9, 2005 |
Process for producing modified polymer
Abstract
A process for producing a modified polymer having, in the
molecule thereof, an organic group(s) introduced thereinto and
derived from a compound(s) having a free radical comprising
reacting a polymer such as an elastomer with a compound having the
free radical stable at an ordinary temperature in the presence of
oxygen, after or while a carbon radical(s) is generated in the
polymer, whereby the modified polymer having an improved
bondability and processability is formed.
Inventors: |
Onoi, Hidekazu; (Kanagawa,
JP) ; Kawazura, Tetsuji; (Kanagawa, JP) ;
Chino, Keisuke; (Kanagawa, JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING
1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Family ID: |
32463312 |
Appl. No.: |
10/501228 |
Filed: |
July 12, 2004 |
PCT Filed: |
December 1, 2003 |
PCT NO: |
PCT/JP03/15354 |
Current U.S.
Class: |
525/242 |
Current CPC
Class: |
C08F 8/50 20130101; C08F
8/30 20130101; C08C 19/00 20130101; C08C 19/22 20130101; C08F 8/50
20130101; C08F 110/06 20130101; C08F 8/30 20130101; C08F 110/06
20130101 |
Class at
Publication: |
525/242 |
International
Class: |
C08F 002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 5, 2002 |
JP |
2002-353831 |
Claims
1. A process for producing a modified polymer having, in the
molecule thereof, an organic group introduced thereinto and derived
from a compound(s) having a free radical(s) comprising reacting a
polymer with a compound(s) having the free radical stable at an
ordinary temperature in the presence of oxygen, after or while a
carbon radical(s) is generated in the polymer.
2. A process for producing a modified polymer as claimed in claim
1, wherein said compound having, in the molecule thereof, a free
radical(s) stably present in the presence of oxygen at ordinary
temperature contains in the molecule thereof at least one free
radical selected from the group consisting of a nitroxide, hydrazyl
radial(s), aryloxy radical(s) and trityl radical(s).
3. A process for producing a modified polymer as claimed in claim 1
or 2, wherein said organic group consisting of a C.sub.1 to
C.sub.30 alkyl group, allyl group, amino group, isocyanate group,
hydroxyl group, thiol group, vinyl group, epoxy group, thiirane
group, carboxyl group, carbonyl-group containing group, amide
group, ester group, imide group, nitrile group, thiocyan group,
C.sub.1 to C.sub.20 alkoxy group, silyl group and alkoxysilyl
group.
4. A process for producing a modified polymer as claimed in claim 1
or 2, wherein a means for generating a carbon radical in said
polymer is at least one means selected from a radical initiator,
electron beam, light and radiation.
5. A process for producing modified polymer as claimed in claim 4,
wherein the amount of use of the radical initiator is 0.1 to 0.6
parts by weight based upon 100 parts by weight of said polymer.
6. A modified polymer obtained by a process according to any one of
1 or 2.
Description
TECHNICAL FIELD
[0001] The present invention relates to a process for producing a
modified polymer, more particularly it relates to a process for
producing a modified polymer by reacting a polymer such as an
elastomer with a compound(s) having a free radical or radicals
stable in the presence of oxygen at ordinary temperature
(hereinafter referred to as "stable free radical").
BACKGROUND ART
[0002] For example, as disclosed in Japanese Unexamined Patent
Publication (Kokai) No. 10-182881, it has been proposed to compound
stable free radicals such as TEMPO (i.e.,
2,2,6,6-tetramethyl-1-piperidinyloxy) into rubber to improve the
physical properties of the rubber composition, in particular those
such as processability, abrasion resistance. Further, Japanese
Unexamined Patent Publication (Kokai) No. 8-239510 proposes to
include a TEMPO derivative in a polymer to prevent polymer aging.
However, no reference can be found relating to positively the
generation of carbon radical or radicals in polymers such as
rubbers so as to modify polymers using a compound(s) having a
stable free radical or the radicals in the molecule thereof.
DISCLOSURE OF THE INVENTION
[0003] Accordingly, the object of the present invention is to
modify a polymer such as an elastomer to improve the bondability
(or adhesion) and processability of the polymer.
[0004] In accordance with the present invention, there is proposed
a process for producing a modified polymer having, in the molecule
thereof, an organic group or groups introduced thereinto and
derived from a compound(s) having a free radical or the radicals
comprising reacting a polymer with a compound(s) having the free
radical or radicals stable at an ordinary temperature in the
presence of oxygen, after or while a carbon radical or radicals are
generated in the polymer.
BEST MODE FOR CARRYING OUT THE INVENTION
[0005] Compounds having a stable free radical or the radicals such
as TEMPO quickly trap radicals produced by the cleavage of rubber
by light, heat, or mechanical action. However, if trying to
introduce functional groups into the molecules of an elastomer, it
is not possible to sufficiently modify the elastomer with only a
compound having stable free radicals such as TEMPO. Therefore, the
inventors succeeded in introducing the desired functional groups
into elastomer molecules by positively causing the generation of
carbon radicals on the polymer molecular chains whereby the present
invention has been completed.
[0006] As polymers capable of being modified according to the
present invention, for example, diene-based rubbers such as natural
rubbers (NR), polyisoprene rubbers (IR), various types of
styrene-butadiene copolymer rubbers (SBR), various types of
polybutadiene rubbers (BR), acrylonitrile butadiene copolymer
rubbers (NBR), butyl rubbers (IIR), chloroprene rubbers (CR);
olefin-based rubbers such as ethylene-propylene copolymer rubbers
(EPM, EPDM), chlorosulfonated polyethylenes (CSM), epichlorohydrin
rubbers (CO, ECO), acryl rubbers (ACM, ANM) and, polysulfide
rubbers (OT) may be illustrated. Further, as thermoplastic
elastomers capable of being modified according to the present
invention, polystyrene-based TPE (SBS, SIS, SEBS), polyolefin-based
TPE, polyvinyl chloride-based TPE, polyurethane-based TPE,
polyester-based TPE, polyurethane-based TPE, polyamide-based TPE,
etc. may be illustrated. Further, as a polyolefin capable of being
modified according to the present invention, for example,
polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC),
chlorinated polymers (CPE, CPP), polystyrene (PS),
styrene-acrylonitrile copolymer (SAN), acrylonitrile butadiene
styrene (ABS), polyamide (PA), acetal resin (POM), polyphenylene
oxide (PPO), polyester, polycarbonate (PC), polysulfone,
polyketone, polyacrylonitrile (PAN), polyimide (PI), liquid crystal
polymer (LCP), etc. may be mentioned.
[0007] On the other hand, as the compounds having, in the molecule
thereof, a free radical or the radicals stable in the presence of
oxygen at ordinary temperature capable of being used in the present
invention, the following compounds may be illustrated.
[0008] Nitroxide Radicals 1
[0009] General Formula 2
[0010] In formulae (1) to (6), R indicates a C.sub.1 to C.sub.30
alkyl group, allyl group, amino group, isocyanate group, hydroxy
group, thiol group, vinyl group, epoxy group, thiirane group,
carboxyl group, carbonyl group-containing group (e.g., cyclic acid
anhydrides such as succinic anhydride, maleic anhydride, glutanic
anhydride, phthalic anhydride,) organic groups containing
functional groups an amide group, ester group, imide group, nitrile
group, thiocyan group, C.sub.1 to C.sub.20 alkoxy group, silyl
group, alkoxysilyl group, nitro group. 34
[0011] Further, other examples may be given as follows: 56
[0012] Hydrazyl Radical 7
[0013] Aryloxy Radical 8
[0014] Trityl Radical 9101112 13
[0015] In the present invention, as the means for generating a
carbon radical or radicals in the polymer, the method of adding a
radical initiator to the reaction system, the method of applying
electron beams, light, heat, and radiation to the reaction system,
etc. may be used. As the radical initiator, for example, organic
peroxides such as benzoyl peroxide (BPO), t-butylperoxybenzoate
(Z), dicumyl peroxide (DCP), t-butylcumyl peroxide (C), t-butyl
peroxide (D), 2,5-dimethyl-2,5-di-t-bu- tylperoxyhexane (2,5B),
2,5-dimethyl-2,5-di-t-butylperoxy-3-hexyne (Hexyne-3),
2,4-dichloro-benzoylperoxide (DC-BPO),
di-t-butylperoxy-di-isopropylbenzene (P),
1,1-bis(t-butylperoxy)-3,3,5-tr- imethyl-cyclohexane (3M),
n-butyl=4,4-bis(t-butylperoxy)valerate,
2,2-bis(t-butylperoxy)butane, and azodicarbonamide (ADCA),
azobisisobutylonitrile (AIBN),
2,2'-azobis-(2-amidinopropane)dihydrochlor- ide, dimethyl
2,2'-azobis(isobutyrate), azobis-cyan valeric acid (ACVA),
1,1'-azobis-(cyclohexane-1-carbonitrile) (ACHN),
2,2'-azobis-(2,4-dimethy- lvaleronitrile) (ADVN), azobismethyl
butylonitrile (AMBN),
2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile), etc. may be
mentioned. These radical generators can generate a carbon radical
or radicals in a polymer by addition to a reaction system of the
polymer and compound having such stable free radicals (mixture
system or catalyzation system). The amount of the radical initiator
added is preferably, based upon 100 parts by weight of the polymer,
0.1 to 6.0 parts by weight, more preferably 0.2 to 3.0 parts by
weight.
[0016] According to the present invention, instead of the radical
initiator or in addition to the radical initiator, it is possible
to use an electron beam (for example, .beta.-rays), light (for
example, UV light) and/or radiation (for example, .gamma.-rays or
X-rays) etc. to generate carbon radicals in the polymer.
[0017] According to the present invention, as the organic group or
groups introduced into the polymer by the modification of the
polymer, for example, a C.sub.1 to C.sub.30 alkyl group, allyl
group, amino group, isocyanate group, hydroxyl group, thiol group,
vinyl group, epoxy group, thiirane group, carboxyl group, carbonyl
group-containing group (for example, cyclic acid anhydrides such as
succinate anhydride, maleic anhydride, glutanic anhydride, phthalic
anhydride; an amide group, ester group, imide group, nitrile group,
thiocyan group, C.sub.1 to C.sub.20 alkoxy group, silyl group,
alkoxysilyl group, etc. may be illustrated.
[0018] In addition to the modified polymer, polymers such as
diene-based rubbers, polyolefin-based rubbers, thermoplastic
elastomer, polyolefins, various additives generally used for tire
use or for other general rubber use reinforcing fillers such as
carbon black or silica, vulcanization or cross-linking agent,
vulcanization or cross-linking accelerator, various types of oils,
anti-aging agent, plasticizer may be blended in. The formulations
are mixed and vulcanized to obtain compositions by general methods
and can be used for vulcanization or cross-linking. The amounts of
these additives used may be made the general amounts used in the
past in so far as the object of the present invention is not
adversely affected.
EXAMPLES
[0019] The present invention will now be explained by the following
Examples, but, of course, the scope of the present invention is not
limited to these Examples.
Examples 1 to 2 and Comparative Examples 1 to 3
[0020] Synthesis of Modifying TEMPO
[0021] 50.68 g of tolylene diisocyanate (TDI made by Sumitomo Bayer
Urethane K.K.) was added to 50.0 g (0.291 mol) of OH-TEMPO (LA7RD
made by Asahi Denka Kogyo K.K.) dissolved in 50 ml of acetone. The
mixture was agitated at room temperature for 24 hours. It was
confirmed that the isocyanate content was 11.96% (theoretical value
12.13%). The acetone was distilled off in vacuo, then the residue
was dried to obtain the final product.
[0022] Production of Modified Polymer
[0023] Based on the formulations shown in Table I (parts by
weight), a polymer (IR) and various compounding agents were mixed
by means of rolls. The mixtures obtained were formed into sheets
and heat treated in 150 mm.times.150 mm.times.2 mm molds at
170.degree. C. for 10 minutes to obtain modified polymers. However,
Comparative Example 3 is a mixture of a polymer and various
compounding agents by means of a roll, without heat treatment.
1TABLE I Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 1 Ex. 2 Ex. 3 IR 100 100
100 100 100 Modifying TEMPO 1 2 1 2 2 Radical 0.98 1.95 -- -- 1.95
initiator Modification 0.23 0.65 0 0 0 rate (wt %) (Notes) IR:
Nipol IR-2200 (Nippon Zeon K.K.) Modifying TEMPOL: See above
Synthesis Radical initiator: Percumyl D-40 (Nihon Oil & Fat
K.K.)
[0024] Modification Rate
[0025] First, a calibration curve for finding the modification rate
of TDI-TEMPO on the polymer was prepared. Mixtures with different
ratios of IR rubber and the modifying TEMPO were uniformly
dissolved in toluene and the mixtures used for IR analysis. The
calibration curve was obtained by averaging the two peak ratios of
the peak ratio of the peak of 1376 cm.sup.-1 of the IR rubber to
the peak of 1727 cm.sup.-1 of the modifying TEMPO and the peak
ratio of the peak of 1448 cm.sup.-1 of the IR rubber to the peak of
1727 cm.sup.-1 of the modifying TEMPO. Similarly, the peak ratios
of the modified polymers fabricated in Table I were calculated and
the calibration curves used to find the modification rates.
[0026] In Table I, Comparative Examples 1 and 2 have no peroxide
added, and therefore sufficient carbon radicals could not be
generated in the polymers and the polymers could not be modified
with the modifying TEMPO. In Comparative Example 3, peroxide was
added, but no heat treatment was performed, and therefore
sufficient carbon radicals could not be generated in the polymer
and the rubber could not be modified with the modifying TEMPO. In
Examples 1 and 2, peroxide was added and heat treatment performed,
and therefore sufficient carbon radicals were generated in the
polymers and the polymers could be modified with the modifying
TEMPO.
Examples 3 to 4 and Comparative Examples 4 to 5
[0027] Synthesis of Modifying TEMPO
[0028] 50.68 g of tolylene diisocyanate (TDI made by Sumitomo Bayer
Urethane K.K.) was added to 50.0 g (0.291 mol) of OH-TEMPO (LA7RD
made by Asahi Denka Kogyo K.K.) dissolved in 50 ml of acetone. The
mixture was agitated at room temperature for 24 hours. It was
confirmed that the isocyanate content was 11.96% (theoretical value
12.13%). The acetone was distilled off in vacuo, then the residue
was dried to obtain the final product.
Method of Preparation of Examples 3 to 4 and Comparative Examples 4
to 5
[0029] Production of Modified Polymer
[0030] Based on the formulations shown in Table II (parts by
weight), in Mixing 1, the ingredients were mixed by a Bambury mixer
adjusted to a temperature of 80.degree. C. and the mixture
discharged when reaching 140.degree. C. to prepare a master batch.
Next, in Mixing 2, the ingredients except for the sulfur and
vulcanization accelerator were mixed in a Bambury mixer adjusted to
a temperature of 60.degree. C. for 5 minutes, then a roll was used
to add the sulfur and vulcanization accelerator and obtain the
unvulcanized rubber.
2 TABLE II Comp. Comp. Ex. 3 Ex. 4 Ex. 4 Ex. 5 Mixing 1 Formulation
(parts by weight) IR 100 100 -- -- Modifying TEMPO 1.2 2.4 -- --
Radical initiator 0.98 1.95 -- -- NP total 102.18 104.35 -- --
Mixing 2 Formulation (parts by weight) NP 102.18 104.35 -- -- IR --
-- 100 100 Modifying TEMPO -- -- 1.2 2.4 Radical initiator -- --
0.98 1.95 Carbon black 60 60 60 60 Zinc white 3 3 3 3 Stearic acid
1 1 1 1 Antioxidant 1 1 1 1 Aromatic oil 5 5 5 5 Sulfur 2.5 2.5 2.5
2.5 Vulcanization 1 1 1 1 accelerator CZ Modification rate 0.35
0.51 0 0 (wt %) Bonding test Pullout force (N) 75 87 12 14 (Notes)
IR: Nipol IR-2200 (made by Nippon Zeon K.K.) Radical initiator:
Percumyl D-40 (Nihon Oil & Fat K.K.) Carbon black: HTC-100
(Chubu Carbon) Stearic acid: Beads Stearic Acid (Nihon Oil &
Fat K.K.) Antioxidant: Nocrac 224 (Ouchi Shinko Chemical Industrial
K.K.) Aromatic oil: Desolex No. 3 (Showa Shell Sekiyu K.K.) Sulfur:
Oil extended sulfur (Karuizawa Refinery K.K.) Vulcanization
accelerator CZ: Noccelar CZ-G (Ouchi Shinko Chemical Industrial
K.K.)
[0031] Method of Fabrication of Bonding Test Samples and Test
Method
[0032] Fiber cord (3300 dtex) composed of one type of polyester
fiber, that is, polyethylene terephthalate fiber (PET), was dipped
in a 2% aqueous solution of an epoxy compound (diglycerol
triglycidyl ether), dried at 120.degree. C. for one minute, then
heat treated at 240.degree. C. for 2 minutes. The polyester fiber
cord thus treated was embedded in a predetermined length in the
unvulcanized rubber which was then vulcanized at 150.degree. C. for
30 minutes to prepare a bonding test sample. The bonding test was
based on the JIS 1017 T-Test Method. The cord was pulled out from
the sample and the pullout force at that time was measured.
[0033] As shown in Table II, in a rubber composition using a master
batch mixed by a Bambury mixer adjusted to a high temperature in
Mixing 1, modification by the modifying TEMPO was confirmed. In
this rubber composition, the bondability with the fiber was
improved, but in rubber compositions where modification was not
confirmed, the bondability with the fiber was not improved.
Examples 5 to 6 and Comparative Examples 6 to 7
[0034] Synthesis of Modifying TEMPO
[0035] 50.68 g of tolylene diisocyanate (TDI made by Sumitomo Bayer
Urethane K.K.) was added to 50.0 g (0.291 mol) of OH-TEMPO (LA7RD
made by Asahi Denka Kogyo K.K.) dissolved in 50 ml of acetone. The
mixture was agitated at room temperature for 24 hours. It was
confirmed that the isocyanate content was 11.96% (theoretical value
12.13%). The acetone was distilled off in vacuo, then the residue
was dried to obtain the final product.
[0036] Production of Modified Polymer
[0037] PP and the various compounding agents were mixed by a
nitrogen-substituted kneader at 200.degree. C. for 15 minutes to
obtain a modified polymer.
[0038] Modification Rate
[0039] A calibration curve for finding the modification rate of
TDI-TEMPO on the PP was prepared. Mixtures with different ratios of
PP and modifying TEMPO were prepared by kneaders and used for IR
analysis. The calibration curve was obtained by averaging the two
peak ratios of the peak ratio of the peak of 1376 cm.sup.-1 of PP
with respect to the peak of 1727 cm.sup.-1 of the modifying TEMPO
and the peak ratio of the peak of 1460 cm.sup.-1 of PP with respect
to the peak of 1727 cm.sup.-1 of the modifying TEMPO. Similarly,
the peak ratios of the modified polymers fabricated in Table III
were calculated and the calibration curves used to find the
modification rates.
3 TABLE III Comp. Comp. Ex. 5 Ex. 6 Ex. 6 Ex. 7 Formulation (parts
by weight) PP 100 100 100 100 Modifying TEMPO 1 2 1 2 DCP 0.5 1 --
-- Modification rate 0.31 0.55 0 0 (wt %) (Notes) PP: Polypropylene
(made by Sumitomo Chemical K.K.) Modifying TEMPO: See above
Synthesis DCP: Dicumyl peroxide (Aldrich Chemical K.K.)
[0040] As shown in Table III, in Examples 5 and 6, modification of
the polymer was confirmed in samples adding modifying TEMPO and
peroxide to PP and mixing them at a high temperature. In
Comparative Examples 6 and 7, peroxide was not added, and therefore
the PP could not be modified.
[0041] Industrial Applicability
[0042] According to the present invention, by modifying a polymer,
the bondability and processability can be improved and the polymer
can be effectively used for rubber products such as tires, conveyor
belts, hoses, and also as plastic products.
* * * * *